vnd.c revision 1.40
1 /* $NetBSD: vnd.c,v 1.40 1997/06/08 15:59:41 pk Exp $ */ 2 3 /* 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * from: Utah $Hdr: vn.c 1.13 94/04/02$ 41 * 42 * @(#)vn.c 8.6 (Berkeley) 4/1/94 43 */ 44 45 /* 46 * Vnode disk driver. 47 * 48 * Block/character interface to a vnode. Allows one to treat a file 49 * as a disk (e.g. build a filesystem in it, mount it, etc.). 50 * 51 * NOTE 1: This uses the VOP_BMAP/VOP_STRATEGY interface to the vnode 52 * instead of a simple VOP_RDWR. We do this to avoid distorting the 53 * local buffer cache. 54 * 55 * NOTE 2: There is a security issue involved with this driver. 56 * Once mounted all access to the contents of the "mapped" file via 57 * the special file is controlled by the permissions on the special 58 * file, the protection of the mapped file is ignored (effectively, 59 * by using root credentials in all transactions). 60 * 61 * NOTE 3: Doesn't interact with leases, should it? 62 */ 63 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/namei.h> 67 #include <sys/proc.h> 68 #include <sys/errno.h> 69 #include <sys/buf.h> 70 #include <sys/malloc.h> 71 #include <sys/ioctl.h> 72 #include <sys/disklabel.h> 73 #include <sys/device.h> 74 #include <sys/disk.h> 75 #include <sys/stat.h> 76 #include <sys/mount.h> 77 #include <sys/vnode.h> 78 #include <sys/file.h> 79 #include <sys/uio.h> 80 #include <sys/conf.h> 81 82 #include <miscfs/specfs/specdev.h> 83 84 #include <dev/vndioctl.h> 85 86 #ifdef DEBUG 87 int dovndcluster = 1; 88 int vnddebug = 0x00; 89 #define VDB_FOLLOW 0x01 90 #define VDB_INIT 0x02 91 #define VDB_IO 0x04 92 #endif 93 94 #define b_cylin b_resid 95 96 #define vndunit(x) DISKUNIT(x) 97 98 struct vndxfer { 99 struct buf *vx_bp; /* Pointer to parent buffer */ 100 int vx_error; 101 int vx_pending; /* # of pending aux buffers */ 102 }; 103 104 struct vndbuf { 105 struct buf vb_buf; 106 struct vndxfer *vb_xfer; 107 }; 108 109 #define getvndxfer() \ 110 ((struct vndxfer *)malloc(sizeof(struct vndxfer), M_DEVBUF, M_WAITOK)) 111 #define putvndxfer(vnx) \ 112 free((caddr_t)(vnx), M_DEVBUF) 113 #define getvndbuf() \ 114 ((struct vndbuf *)malloc(sizeof(struct vndbuf), M_DEVBUF, M_WAITOK)) 115 #define putvndbuf(vbp) \ 116 free((caddr_t)(vbp), M_DEVBUF) 117 118 struct vnd_softc { 119 int sc_flags; /* flags */ 120 size_t sc_size; /* size of vnd */ 121 struct vnode *sc_vp; /* vnode */ 122 struct ucred *sc_cred; /* credentials */ 123 int sc_maxactive; /* max # of active requests */ 124 struct buf sc_tab; /* transfer queue */ 125 char sc_xname[8]; /* XXX external name */ 126 struct disk sc_dkdev; /* generic disk device info */ 127 }; 128 129 /* sc_flags */ 130 #define VNF_ALIVE 0x01 131 #define VNF_INITED 0x02 132 #define VNF_WANTED 0x40 133 #define VNF_LOCKED 0x80 134 135 struct vnd_softc *vnd_softc; 136 int numvnd = 0; 137 138 /* called by main() at boot time */ 139 void vndattach __P((int)); 140 141 void vndclear __P((struct vnd_softc *)); 142 void vndstart __P((struct vnd_softc *)); 143 int vndsetcred __P((struct vnd_softc *, struct ucred *)); 144 void vndthrottle __P((struct vnd_softc *, struct vnode *)); 145 void vndiodone __P((struct buf *)); 146 void vndshutdown __P((void)); 147 148 static int vndlock __P((struct vnd_softc *)); 149 static void vndunlock __P((struct vnd_softc *)); 150 151 void 152 vndattach(num) 153 int num; 154 { 155 char *mem; 156 register u_long size; 157 158 if (num <= 0) 159 return; 160 size = num * sizeof(struct vnd_softc); 161 mem = malloc(size, M_DEVBUF, M_NOWAIT); 162 if (mem == NULL) { 163 printf("WARNING: no memory for vnode disks\n"); 164 return; 165 } 166 bzero(mem, size); 167 vnd_softc = (struct vnd_softc *)mem; 168 numvnd = num; 169 } 170 171 int 172 vndopen(dev, flags, mode, p) 173 dev_t dev; 174 int flags, mode; 175 struct proc *p; 176 { 177 int unit = vndunit(dev); 178 struct vnd_softc *sc; 179 int error = 0, part, pmask; 180 181 /* 182 * XXX Should support disklabels. 183 */ 184 185 #ifdef DEBUG 186 if (vnddebug & VDB_FOLLOW) 187 printf("vndopen(%x, %x, %x, %p)\n", dev, flags, mode, p); 188 #endif 189 if (unit >= numvnd) 190 return (ENXIO); 191 sc = &vnd_softc[unit]; 192 193 if ((error = vndlock(sc)) != 0) 194 return (error); 195 196 part = DISKPART(dev); 197 pmask = (1 << part); 198 199 /* Prevent our unit from being unconfigured while open. */ 200 switch (mode) { 201 case S_IFCHR: 202 sc->sc_dkdev.dk_copenmask |= pmask; 203 break; 204 205 case S_IFBLK: 206 sc->sc_dkdev.dk_bopenmask |= pmask; 207 break; 208 } 209 sc->sc_dkdev.dk_openmask = 210 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 211 212 vndunlock(sc); 213 return (0); 214 } 215 216 int 217 vndclose(dev, flags, mode, p) 218 dev_t dev; 219 int flags, mode; 220 struct proc *p; 221 { 222 int unit = vndunit(dev); 223 struct vnd_softc *sc; 224 int error = 0, part; 225 226 #ifdef DEBUG 227 if (vnddebug & VDB_FOLLOW) 228 printf("vndclose(%x, %x, %x, %p)\n", dev, flags, mode, p); 229 #endif 230 231 if (unit >= numvnd) 232 return (ENXIO); 233 sc = &vnd_softc[unit]; 234 235 if ((error = vndlock(sc)) != 0) 236 return (error); 237 238 part = DISKPART(dev); 239 240 /* ...that much closer to allowing unconfiguration... */ 241 switch (mode) { 242 case S_IFCHR: 243 sc->sc_dkdev.dk_copenmask &= ~(1 << part); 244 break; 245 246 case S_IFBLK: 247 sc->sc_dkdev.dk_bopenmask &= ~(1 << part); 248 break; 249 } 250 sc->sc_dkdev.dk_openmask = 251 sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask; 252 253 vndunlock(sc); 254 return (0); 255 } 256 257 /* 258 * Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY. 259 * Note that this driver can only be used for swapping over NFS on the hp 260 * since nfs_strategy on the vax cannot handle u-areas and page tables. 261 */ 262 void 263 vndstrategy(bp) 264 register struct buf *bp; 265 { 266 int unit = vndunit(bp->b_dev); 267 struct vnd_softc *vnd = &vnd_softc[unit]; 268 struct vndbuf *nbp; 269 struct vndxfer *vnx; 270 int bn, bsize, resid; 271 caddr_t addr; 272 int sz, flags, error; 273 274 #ifdef DEBUG 275 if (vnddebug & VDB_FOLLOW) 276 printf("vndstrategy(%p): unit %d\n", bp, unit); 277 #endif 278 if ((vnd->sc_flags & VNF_INITED) == 0) { 279 bp->b_error = ENXIO; 280 bp->b_flags |= B_ERROR; 281 biodone(bp); 282 return; 283 } 284 bn = bp->b_blkno; 285 sz = howmany(bp->b_bcount, DEV_BSIZE); 286 bp->b_resid = bp->b_bcount; 287 if (bn < 0 || bn + sz > vnd->sc_size) { 288 if (bn != vnd->sc_size) { 289 bp->b_error = EINVAL; 290 bp->b_flags |= B_ERROR; 291 } 292 biodone(bp); 293 return; 294 } 295 bn = dbtob(bn); 296 bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize; 297 addr = bp->b_data; 298 flags = bp->b_flags | B_CALL; 299 300 /* Allocate a header for this transfer and link it to the buffer */ 301 vnx = getvndxfer(); 302 vnx->vx_error = 0; 303 vnx->vx_pending = 0; 304 vnx->vx_bp = bp; 305 306 for (resid = bp->b_resid; resid; resid -= sz) { 307 struct vnode *vp; 308 daddr_t nbn; 309 int off, s, nra; 310 311 nra = 0; 312 VOP_LOCK(vnd->sc_vp); 313 error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra); 314 VOP_UNLOCK(vnd->sc_vp); 315 316 if (error == 0 && (long)nbn == -1) 317 error = EIO; 318 319 /* 320 * If there was an error or a hole in the file...punt. 321 * Note that we may have to wait for any operations 322 * that we have already fired off before releasing 323 * the buffer. 324 * 325 * XXX we could deal with holes here but it would be 326 * a hassle (in the write case). 327 */ 328 if (error) { 329 vnx->vx_error = error; 330 s = splbio(); 331 if (vnx->vx_pending == 0) { 332 bp->b_error = error; 333 bp->b_flags |= B_ERROR; 334 putvndxfer(vnx); 335 biodone(bp); 336 } 337 splx(s); 338 return; 339 } 340 341 #ifdef DEBUG 342 if (!dovndcluster) 343 nra = 0; 344 #endif 345 346 if ((off = bn % bsize) != 0) 347 sz = bsize - off; 348 else 349 sz = (1 + nra) * bsize; 350 if (resid < sz) 351 sz = resid; 352 #ifdef DEBUG 353 if (vnddebug & VDB_IO) 354 printf("vndstrategy: vp %p/%p bn %x/%x sz %x\n", 355 vnd->sc_vp, vp, bn, nbn, sz); 356 #endif 357 358 nbp = getvndbuf(); 359 nbp->vb_buf.b_flags = flags; 360 nbp->vb_buf.b_bcount = sz; 361 nbp->vb_buf.b_bufsize = bp->b_bufsize; 362 nbp->vb_buf.b_error = 0; 363 if (vp->v_type == VBLK || vp->v_type == VCHR) 364 nbp->vb_buf.b_dev = vp->v_rdev; 365 else 366 nbp->vb_buf.b_dev = NODEV; 367 nbp->vb_buf.b_data = addr; 368 nbp->vb_buf.b_blkno = nbn + btodb(off); 369 nbp->vb_buf.b_proc = bp->b_proc; 370 nbp->vb_buf.b_iodone = vndiodone; 371 nbp->vb_buf.b_vp = vp; 372 nbp->vb_buf.b_rcred = vnd->sc_cred; /* XXX crdup? */ 373 nbp->vb_buf.b_wcred = vnd->sc_cred; /* XXX crdup? */ 374 if (bp->b_dirtyend == 0) { 375 nbp->vb_buf.b_dirtyoff = 0; 376 nbp->vb_buf.b_dirtyend = sz; 377 } else { 378 nbp->vb_buf.b_dirtyoff = 379 max(0, bp->b_dirtyoff - (bp->b_bcount - resid)); 380 nbp->vb_buf.b_dirtyend = 381 min(sz, 382 max(0, bp->b_dirtyend - (bp->b_bcount-resid))); 383 } 384 if (bp->b_validend == 0) { 385 nbp->vb_buf.b_validoff = 0; 386 nbp->vb_buf.b_validend = sz; 387 } else { 388 nbp->vb_buf.b_validoff = 389 max(0, bp->b_validoff - (bp->b_bcount - resid)); 390 nbp->vb_buf.b_validend = 391 min(sz, 392 max(0, bp->b_validend - (bp->b_bcount-resid))); 393 } 394 395 nbp->vb_xfer = vnx; 396 397 /* 398 * Just sort by block number 399 */ 400 nbp->vb_buf.b_cylin = nbp->vb_buf.b_blkno; 401 s = splbio(); 402 vnx->vx_pending++; 403 disksort(&vnd->sc_tab, &nbp->vb_buf); 404 if (vnd->sc_tab.b_active < vnd->sc_maxactive) { 405 vnd->sc_tab.b_active++; 406 vndstart(vnd); 407 } 408 splx(s); 409 bn += sz; 410 addr += sz; 411 } 412 } 413 414 /* 415 * Feed requests sequentially. 416 * We do it this way to keep from flooding NFS servers if we are connected 417 * to an NFS file. This places the burden on the client rather than the 418 * server. 419 */ 420 void 421 vndstart(vnd) 422 register struct vnd_softc *vnd; 423 { 424 register struct buf *bp; 425 426 /* 427 * Dequeue now since lower level strategy routine might 428 * queue using same links 429 */ 430 bp = vnd->sc_tab.b_actf; 431 vnd->sc_tab.b_actf = bp->b_actf; 432 #ifdef DEBUG 433 if (vnddebug & VDB_IO) 434 printf("vndstart(%ld): bp %p vp %p blkno %x addr %p cnt %lx\n", 435 (long) (vnd-vnd_softc), bp, bp->b_vp, bp->b_blkno, 436 bp->b_data, bp->b_bcount); 437 #endif 438 439 /* Instrumentation. */ 440 disk_busy(&vnd->sc_dkdev); 441 442 if ((bp->b_flags & B_READ) == 0) 443 bp->b_vp->v_numoutput++; 444 VOP_STRATEGY(bp); 445 } 446 447 void 448 vndiodone(bp) 449 struct buf *bp; 450 { 451 register struct vndbuf *vbp = (struct vndbuf *) bp; 452 register struct vndxfer *vnx = (struct vndxfer *)vbp->vb_xfer; 453 register struct buf *pbp = vnx->vx_bp; 454 register struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)]; 455 int s, resid; 456 457 s = splbio(); 458 #ifdef DEBUG 459 if (vnddebug & VDB_IO) 460 printf("vndiodone(%ld): vbp %p vp %p blkno %x addr %p cnt %lx\n", 461 (long) (vnd-vnd_softc), vbp, vbp->vb_buf.b_vp, 462 vbp->vb_buf.b_blkno, vbp->vb_buf.b_data, 463 vbp->vb_buf.b_bcount); 464 #endif 465 466 resid = vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid; 467 pbp->b_resid -= resid; 468 disk_unbusy(&vnd->sc_dkdev, resid); 469 vnx->vx_pending--; 470 471 if (vbp->vb_buf.b_error) { 472 #ifdef DEBUG 473 if (vnddebug & VDB_IO) 474 printf("vndiodone: vbp %p error %d\n", vbp, 475 vbp->vb_buf.b_error); 476 #endif 477 vnx->vx_error = vbp->vb_buf.b_error; 478 } 479 putvndbuf(vbp); 480 481 /* 482 * Wrap up this transaction if it has run to completion or, in 483 * case of an error, when all auxiliary buffers have returned. 484 */ 485 if (pbp->b_resid == 0 || (vnx->vx_error && vnx->vx_pending == 0)) { 486 487 if (vnx->vx_error != 0) { 488 pbp->b_flags |= B_ERROR; 489 pbp->b_error = vnx->vx_error; 490 } 491 putvndxfer(vnx); 492 #ifdef DEBUG 493 if (vnddebug & VDB_IO) 494 printf("vndiodone: pbp %p iodone\n", pbp); 495 #endif 496 biodone(pbp); 497 } 498 499 if (vnd->sc_tab.b_actf) 500 vndstart(vnd); 501 else 502 vnd->sc_tab.b_active--; 503 splx(s); 504 } 505 506 /* ARGSUSED */ 507 int 508 vndread(dev, uio, flags) 509 dev_t dev; 510 struct uio *uio; 511 int flags; 512 { 513 int unit = vndunit(dev); 514 struct vnd_softc *sc; 515 516 #ifdef DEBUG 517 if (vnddebug & VDB_FOLLOW) 518 printf("vndread(%x, %p)\n", dev, uio); 519 #endif 520 521 if (unit >= numvnd) 522 return (ENXIO); 523 sc = &vnd_softc[unit]; 524 525 if ((sc->sc_flags & VNF_INITED) == 0) 526 return (ENXIO); 527 528 return (physio(vndstrategy, NULL, dev, B_READ, minphys, uio)); 529 } 530 531 /* ARGSUSED */ 532 int 533 vndwrite(dev, uio, flags) 534 dev_t dev; 535 struct uio *uio; 536 int flags; 537 { 538 int unit = vndunit(dev); 539 struct vnd_softc *sc; 540 541 #ifdef DEBUG 542 if (vnddebug & VDB_FOLLOW) 543 printf("vndwrite(%x, %p)\n", dev, uio); 544 #endif 545 546 if (unit >= numvnd) 547 return (ENXIO); 548 sc = &vnd_softc[unit]; 549 550 if ((sc->sc_flags & VNF_INITED) == 0) 551 return (ENXIO); 552 553 return (physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio)); 554 } 555 556 /* ARGSUSED */ 557 int 558 vndioctl(dev, cmd, data, flag, p) 559 dev_t dev; 560 u_long cmd; 561 caddr_t data; 562 int flag; 563 struct proc *p; 564 { 565 int unit = vndunit(dev); 566 register struct vnd_softc *vnd; 567 struct vnd_ioctl *vio; 568 struct vattr vattr; 569 struct nameidata nd; 570 int error, part, pmask; 571 572 #ifdef DEBUG 573 if (vnddebug & VDB_FOLLOW) 574 printf("vndioctl(%x, %lx, %p, %x, %p): unit %d\n", 575 dev, cmd, data, flag, p, unit); 576 #endif 577 error = suser(p->p_ucred, &p->p_acflag); 578 if (error) 579 return (error); 580 if (unit >= numvnd) 581 return (ENXIO); 582 583 vnd = &vnd_softc[unit]; 584 vio = (struct vnd_ioctl *)data; 585 switch (cmd) { 586 587 case VNDIOCSET: 588 if (vnd->sc_flags & VNF_INITED) 589 return (EBUSY); 590 591 if ((error = vndlock(vnd)) != 0) 592 return (error); 593 594 /* 595 * Always open for read and write. 596 * This is probably bogus, but it lets vn_open() 597 * weed out directories, sockets, etc. so we don't 598 * have to worry about them. 599 */ 600 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vnd_file, p); 601 if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) { 602 vndunlock(vnd); 603 return(error); 604 } 605 error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p); 606 if (error) { 607 VOP_UNLOCK(nd.ni_vp); 608 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 609 vndunlock(vnd); 610 return(error); 611 } 612 VOP_UNLOCK(nd.ni_vp); 613 vnd->sc_vp = nd.ni_vp; 614 vnd->sc_size = btodb(vattr.va_size); /* note truncation */ 615 if ((error = vndsetcred(vnd, p->p_ucred)) != 0) { 616 (void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p); 617 vndunlock(vnd); 618 return(error); 619 } 620 vndthrottle(vnd, vnd->sc_vp); 621 vio->vnd_size = dbtob(vnd->sc_size); 622 vnd->sc_flags |= VNF_INITED; 623 #ifdef DEBUG 624 if (vnddebug & VDB_INIT) 625 printf("vndioctl: SET vp %p size %lx\n", 626 vnd->sc_vp, (unsigned long) vnd->sc_size); 627 #endif 628 629 /* Attach the disk. */ 630 bzero(vnd->sc_xname, sizeof(vnd->sc_xname)); /* XXX */ 631 sprintf(vnd->sc_xname, "vnd%d", unit); /* XXX */ 632 vnd->sc_dkdev.dk_name = vnd->sc_xname; 633 disk_attach(&vnd->sc_dkdev); 634 635 vndunlock(vnd); 636 637 break; 638 639 case VNDIOCCLR: 640 if ((vnd->sc_flags & VNF_INITED) == 0) 641 return (ENXIO); 642 643 if ((error = vndlock(vnd)) != 0) 644 return (error); 645 646 /* 647 * Don't unconfigure if any other partitions are open 648 * or if both the character and block flavors of this 649 * partition are open. 650 */ 651 part = DISKPART(dev); 652 pmask = (1 << part); 653 if ((vnd->sc_dkdev.dk_openmask & ~pmask) || 654 ((vnd->sc_dkdev.dk_bopenmask & pmask) && 655 (vnd->sc_dkdev.dk_copenmask & pmask))) { 656 vndunlock(vnd); 657 return (EBUSY); 658 } 659 660 vndclear(vnd); 661 #ifdef DEBUG 662 if (vnddebug & VDB_INIT) 663 printf("vndioctl: CLRed\n"); 664 #endif 665 666 /* Detatch the disk. */ 667 disk_detach(&vnd->sc_dkdev); 668 669 vndunlock(vnd); 670 671 break; 672 673 /* 674 * XXX Should support disklabels. 675 */ 676 677 default: 678 return(ENOTTY); 679 } 680 681 return (0); 682 } 683 684 /* 685 * Duplicate the current processes' credentials. Since we are called only 686 * as the result of a SET ioctl and only root can do that, any future access 687 * to this "disk" is essentially as root. Note that credentials may change 688 * if some other uid can write directly to the mapped file (NFS). 689 */ 690 int 691 vndsetcred(vnd, cred) 692 register struct vnd_softc *vnd; 693 struct ucred *cred; 694 { 695 struct uio auio; 696 struct iovec aiov; 697 char *tmpbuf; 698 int error; 699 700 vnd->sc_cred = crdup(cred); 701 tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK); 702 703 /* XXX: Horrible kludge to establish credentials for NFS */ 704 aiov.iov_base = tmpbuf; 705 aiov.iov_len = min(DEV_BSIZE, dbtob(vnd->sc_size)); 706 auio.uio_iov = &aiov; 707 auio.uio_iovcnt = 1; 708 auio.uio_offset = 0; 709 auio.uio_rw = UIO_READ; 710 auio.uio_segflg = UIO_SYSSPACE; 711 auio.uio_resid = aiov.iov_len; 712 VOP_LOCK(vnd->sc_vp); 713 error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred); 714 VOP_UNLOCK(vnd->sc_vp); 715 716 free(tmpbuf, M_TEMP); 717 return (error); 718 } 719 720 /* 721 * Set maxactive based on FS type 722 */ 723 void 724 vndthrottle(vnd, vp) 725 register struct vnd_softc *vnd; 726 struct vnode *vp; 727 { 728 #ifdef NFS 729 extern int (**nfsv2_vnodeop_p) __P((void *)); 730 731 if (vp->v_op == nfsv2_vnodeop_p) 732 vnd->sc_maxactive = 2; 733 else 734 #endif 735 vnd->sc_maxactive = 8; 736 737 if (vnd->sc_maxactive < 1) 738 vnd->sc_maxactive = 1; 739 } 740 741 void 742 vndshutdown() 743 { 744 register struct vnd_softc *vnd; 745 746 for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++) 747 if (vnd->sc_flags & VNF_INITED) 748 vndclear(vnd); 749 } 750 751 void 752 vndclear(vnd) 753 register struct vnd_softc *vnd; 754 { 755 register struct vnode *vp = vnd->sc_vp; 756 struct proc *p = curproc; /* XXX */ 757 758 #ifdef DEBUG 759 if (vnddebug & VDB_FOLLOW) 760 printf("vndclear(%p): vp %p\n", vnd, vp); 761 #endif 762 vnd->sc_flags &= ~VNF_INITED; 763 if (vp == (struct vnode *)0) 764 panic("vndioctl: null vp"); 765 (void) vn_close(vp, FREAD|FWRITE, vnd->sc_cred, p); 766 crfree(vnd->sc_cred); 767 vnd->sc_vp = (struct vnode *)0; 768 vnd->sc_cred = (struct ucred *)0; 769 vnd->sc_size = 0; 770 } 771 772 int 773 vndsize(dev) 774 dev_t dev; 775 { 776 int unit = vndunit(dev); 777 register struct vnd_softc *vnd = &vnd_softc[unit]; 778 779 if (unit >= numvnd || (vnd->sc_flags & VNF_INITED) == 0) 780 return(-1); 781 return(vnd->sc_size); 782 } 783 784 int 785 vnddump(dev, blkno, va, size) 786 dev_t dev; 787 daddr_t blkno; 788 caddr_t va; 789 size_t size; 790 { 791 792 /* Not implemented. */ 793 return ENXIO; 794 } 795 796 /* 797 * Wait interruptibly for an exclusive lock. 798 * 799 * XXX 800 * Several drivers do this; it should be abstracted and made MP-safe. 801 */ 802 static int 803 vndlock(sc) 804 struct vnd_softc *sc; 805 { 806 int error; 807 808 while ((sc->sc_flags & VNF_LOCKED) != 0) { 809 sc->sc_flags |= VNF_WANTED; 810 if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0) 811 return (error); 812 } 813 sc->sc_flags |= VNF_LOCKED; 814 return (0); 815 } 816 817 /* 818 * Unlock and wake up any waiters. 819 */ 820 static void 821 vndunlock(sc) 822 struct vnd_softc *sc; 823 { 824 825 sc->sc_flags &= ~VNF_LOCKED; 826 if ((sc->sc_flags & VNF_WANTED) != 0) { 827 sc->sc_flags &= ~VNF_WANTED; 828 wakeup(sc); 829 } 830 } 831
Indexes created Mon Sep 29 21:09:56 GMT 2025